There’s no evidence that gluten, a protein found in wheat and some other cereal grains, causes digestive problems in people who don’t have a gluten-related disorder (celiac disease or non-celiac gluten sensitivity), according to the first double-blind randomized controlled trial to put this dietary fad to the test.
Many people, including a number of celebrities and athletes, promote gluten-free diets as a healthy lifestyle choice and cure for numerous ailments, despite a lack of convincing evidence of benefits. A few years ago, the market research company Mintel reported that nearly half of Americans (44 percent) eat gluten-free foods for reasons unrelated to gluten intolerance or sensitivity.
Published in the journal Gastroenterology, the study included 28 healthy people who all tested negative for celiac disease but reported some digestive complaints. For two weeks, they ate a gluten-free diet, as instructed by a dietitian, after which they were divided into two groups: one that added a packet of gluten-containing flour to their food twice a day for two weeks (for a total of 14 grams of gluten a day), the other that added gluten-free flour. Both groups continued a gluten-free diet while incorporating the flour, with neither group aware of which flour they were consuming.
Based on a questionnaire completed by the participants at the start and end of the study that assessed gastrointestinal symptoms, no differences were seen between the two groups in abdominal pain, diarrhea, constipation, reflux, or indigestion at either point. “Our results support the view that gluten does not appear to cause symptoms in individuals who do not have a physiological susceptibility to it (i.e., most of the population),” the researchers concluded.
Bottom line:There’s no reason to go on a gluten-free diet because you think it is healthier. It may in fact be less well balanced than a diet that contains gluten. In some cases, however, people with some forms of irritable bowel syndrome, such as those that are diarrhea predominant, may get improvement from a gluten-free diet, according to Steve Jacobsohn, M.D., a gastroenterologist and member of our editorial board. Still, a gluten-free diet should never be initiated without first seeing your doctor and being tested for celiac disease. This disorder requires additional care and follow-up, and its diagnosis will likely be missed if gluten is withdrawn before blood testing is done.
This article first appeared in the UC Berkeley Wellness Letter.
Also see Lectins: The New Gluten?